Question

Se stie ca (7^4+7^5)*49=x^3.Atunci:
A.x=98 B.x=14 C.x=18 d.x=89
Dati-mi va rog raspuns si calcul intreg.

Answer 1

[tex](7^4+7^5)*49=x^3\\ (7^4+7^5)*7^2=x^3\\ 7^6+7^7=x^3\\ 7^6(1+7)=x^3\\ (7^2)^3*8=x^3\\ (7^2)^3*2^3=x^3\\ (7^2*2)^3=x^3\\ x=7^2*2=98[/tex]